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6. Risultati

6.2 Risultati della procedura di stima dei raccolti

6.2.2 Risultati della simulazione

In Tab. V, sono sono raccolte le coordinate geografiche di siti campione su cui sono state condotte le simulazioni, e la specie agricole ivi presenti. In Fig. 6.6 sono mostrate le serie storiche FAO dei livelli di produzione (valori medi per il Kenya) delle due specie agricole analizzate; evidenziati in giallo, i valori relativi all’anno 2015 relativi alle simulazioni condotte, appaiono del tutto coerenti con i valori di riferimento medi presentati. In Tab.VI sono invece disponibili i rapporti completi relativi alle simulazioni condotte; è possibile vedere come non siano stati presi in considerazione fattori di stress come la salinizzazione del suolo o particolari deficit della fertilità del terreno. Tuttavia fattori di stress termico, come pure elevati livelli di sofferenza al livello foliare e degli stomi, sono determinanti nel determinare una drastica riduzione dell’HI, da valori di riferimento prossimi al 48%, sino a valori del 18-23%.

Tabella V Siti campione

Sample Type Lon Lat

Sample field n. 1 Maize 35.92187 E 0.30612 N

Sample field n. 2 Maize 35.94662 E 0.34212 N

Sample field n. 3 Maize 35.92412 E 0.35112 N

Sample field n. 4 Maize 35.92412 E 0.35337 N

Sample field n. 5 Wheat 35.92187 E 0.30612 N

Sample field n. 6 Wheat 35.94212 E 0.34662 N

Sample field n. 7 Wheat 35.94662 E 0.34662 N

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Tabella VI

Sintesi simulazioni AquaCrop

s.f. 1 s.f. 2 s.f. 3 s.f. 4 s.f. 5 s.f. 6 s.f. 7 Day1 22 22 7 15 1 1 15 Month1 3 3 4 3 3 3 3 Year1 2015 2015 2015 2015 2015 2015 2015 Rain mm 190 190 176 201 334 339 374 ETo mm 441 435 434 446 603 601 586 GD °C.day 1001 1001 1027 967 2950 2953 2947 CO2 ppm 400.55 400.55 400.55 400.55 400.55 400.55 400.55 Irri mm 0 0 0 0 0 0 0 Infilt mm 190 190 176 201 333 338 368 Runoff mm 0 0 0 0 1 1 6 Drain mm 0 0 0 0 0 0 0 Upflow mm 0 0 0 0 0 0 0 E mm 166 164 164 174 255 256 253 E/Ex % 70 71 69 71 81 82 83 Tr mm 125 126 109 126 155 155 143 TrW mm 125 126 109 126 155 155 143 Tr/Trx % 80 81 77 82 73 73 70 SaltIn ton/ha 0.000 0.000 0.000 0.000 0.000 0.000 0.000 SaltOut ton/ha 0.000 0.000 0.000 0.000 0.000 0.000 0.000 SaltUp ton/ha 0.000 0.000 0.000 0.000 0.000 0.000 0.000 SaltProf ton/ha 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Cycle days 93 94 93 92 112 112 113 SaltStr % 0 0 0 0 0 0 0 FertStr % 0 0 0 0 0 0 0 WeedStr % 0 0 0 0 0 0 0 TempStr % 21 21 24 22 0 0 0 ExpStr % 33 32 26 33 32 32 30 StoStr % 20 20 21 18 34 34 39 BioMass ton/ha 9.863 10.113 7.678 9.374 7.877 7.940 7.539 Brelative % 52 54 45 50 31 32 30 HI % 17.5 18.4 17.6 18.1 27.3 27.5 22.8 Yield ton/ha 1.725 1.865 1.350 1.698 2.154 2.179 1.716 WPet kg/m3 0.72 0.78 0.63 0.67 0.68 0.69 0.60 DayN 15 15 31 8 11 12 27 MonthN 8 8 8 8 9 9 9 YearN 2015 2015 2015 2015 2015 2015 2015

Day1, Start day of simulation run; Month1, Start month of simulation run; Year1, Start year of simulation run; Rain , Rainfall; ETo, Reference evapotranspiration; GD, Growing degrees; CO2, Atmospheric CO2 concentration; Irri, Water applied by

irrigation; Infilt, Infiltrated water in soil profile; Runoff, Water lost by surface runoff; Drain, Water drained out of the soil profile;

Upflow, Water moved upward by capillary rise; E, Soil evaporation; E/Ex, Relative soil evaporation (100 E/Ex); Tr, Total

transpiration of crop; TrW, Crop transpiration by weed infestation; Tr/Trx, Relative total transpiration (100 Tr/Trx); SaltIn, Salt infiltrated in the soil profile; SaltOut, Salt drained out of the soil profile; SaltUp, Salt moved upward by capillary rise from groundwater table; SaltProf, Salt stored in the soil profile; Cycle, Length of crop cycle; SaltStr, Soil salinity stress; FertStr, Soil fertility stress; WeedStr, Relative cover of weeds at canopy closure; TempStr, Temperature stress; ExpStr, Leaf expansion stress;

StoStr, Stomatal stress; Biomass, Cumulative biomass produced; Brelative Relative biomass; HI, Harvest Index adjusted for

inadequate photosynthesis and water stress; Yield, Yield (HI x Biomass); WPet, ET Water Productivity for yield part (kg yield produced per m3 water evapotranspired); DayN, End day of simulation run; MonthN, End month of simulation run; YearN, End year of simulation run.

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6.2.3 Conclusioni

In quessto studio il modello AquaCrop è stato impiegato per stimare i livelli di copertura fogliare, biomassa e raccolto di due specie agricole, in risposta al deficit di irrigazione in condizioni di clima sub-umido e semi-arido, tipico delle highlands keniane. Dati osservati sulle aree di test sono stati forniti dagli archivi della FAO e dall’USDA FAS (United States Department of Agriculture, Foreign Agricultural Service). La distanza fra stima ed osservazione dei raccolti di mais e grano nei siti in analisi (Fig. 6.7), è soddisfacente, con valori di R pari a 0.71 e 0.66 e MAE pari a 216 kg/ha e

650 kg/ha, rispettivamente per le due specie. Si può concludere che il modello AquaCrop può essere un valido strumento nella pianificazione e gestione delle attività agricole, in particolar modo considerando il fatto che il modello di simulazione richiede un numero limitato di parametri, in gran parte intuitivi ed espliciti, facilmente collezionabili (anche secondo procedure suscettibili di automazione) che, in molti casi, sono già disponibili. Non di meno le prestazioni del modello necessitano una più vasta ed approfondita validazione e valutazione, in funzione delle diverse possibili calibrazioni, e di una più ampia disponibilità di siti campione e specie agricole.

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Bibliografia

Allen W.A., Gausman H.W., Richardson A.J., Thomas J.R., 1969. Interaction of isotropic light with a compact plant leaf. Journal of the Optical Society of America, 59, 1376-1379.

Antoine, J. 1994. Linking geographical information systems (GIS) and FAO’s agroecological zone (AEZ) models for land resource appraisal. Pp 35-52. In: Proceedings of the regional workshop on Agro-Ecological Zones methodology and Applications. Bangkok, Thailand 17-23 November 1991. World Soil resources Report 75. Rome

Balsamo G., Albergel C., Beljaars A., Boussetta S., Brun E., Cloke H., Dee D., Dutra E., Muñoz-Sabater J., Pappenberger F., de Rosnay P., Stockdale T. and Vitart F., 2015. ERA-Interim/Land: a global land surface reanalysis data set. Hydrol. Earth Syst. Sci., 19, 389–407, 2015

Batjes, N.H., 2002. ISRIC-WISE global data set of derived soil properties on a 0.5 by 0.5 degree grid (Version 2.0). Report 2002/03 (available online via: http:\\www.isric.org). International Soil Reference and Information Centre (ISRIC), Wageningen.

Becker-Reshef, I.; Justice, C.O.; Sullivan, M.; Vermote, E.F.; Tucker, C.; Anyamba, A.; Small, J.; Pak, E.; Masuoka, E.; Schmaltz, J.; et al. Monitoring global croplands with coarse resolution Earth observation: The Global Agriculture Monitoring (GLAM) project. Remote Sens 2010, 2, 1589–1609. Berrisford, Paul & Dee, D & Fielding, K & Fuentes, M & Kallberg, Per & Kobayashi, Shinya & Uppala,

S. M.. (2009). The ERA-interim archive.

Bhattacharya, B.K. and Sastry, P.S. 1999. Comparative evaluation of three-crop growth models for the simulation of soil water balance in oilseed Brassica. Agr. Water Manage. 42: 29-46.

Boryan C., Yang Z., Mueller R. and Craig M., 2011. Monitoring US agriculture: the US Department of Agriculture, National Agricultural Statistics Service, Cropland Data Layer Program. Geocarto International Vol. 26 , Iss. 5,2011

Brodley C.E., Utgoff P. E., 1992. Multivariate Decision Trees. COINS Technical Report 92-82 Brodley C.E., Utgoff P. E., 1995. Multivariate Decision Trees. Machine Learning, 19. 45-77.

Brown de Colstoun E., M. Story, C. Thompson, K. Commisso, T. Smith, and J. Irons. 2003. National park vegetation mapping using multitemporal Landsat 7 data and a decision tree classifier. Remote Sensing of Environment 85:316-327.

Buschmann C., Nagel E., 1993. In vivo spectroscopy and internal optics of leaves as basis for remote sensing of vegetation. International Journal of Remote sensing, 14, 711-722.

Curcio J.A., Petty C.C., 1951. Extinctions coefficients for pure liquid water. Journal of Optical Society of America, 41, 302-304.

- 100 -

Dawson T.P., Curran P.J., 1998. A new technique for interpolating the reflectance red edge position. International Journal of Remote Sensing, 19, 2133-2139.

Domaç A. & Süzen ML., 2006, ‘Integration of environmental variables with satellite images in regional scale vegetation classification’, Int. J. Remote Sens., vol. 27, pp. 1329-1350.

Doorenbos, J. and Kassam, A.H. 1979. Yield response to water. FAO Irrigation and Drainage Paper No. 33, FAO, Rome, Italy. 193 pp.

Eller B.M:, 1977. Leaf pubescence: the significance of lower surface hairs for the spectral properties of the upper surface. Journal of Experimental Botany, 28, 1054-1059.

Evett, S.R. and Tolk, J.A. 2009. Introduction: Can Water UseEfficiency be Modeled. Agron. J. 101: 423-425.

FAO. 1978. Report on Agro-Ecological Zones Project. Vol 1. Methodology and Results for Africa. World Soil Resources Report 48. FAO: Rome.

FAO, 1982. Potential population supporting capacities of lands in the developing world. Technical Report of project INT/75/P13, ‘Land resources for populations of the future’, undertaken by FAO/IIASA for UNFPA.

FAO/IIASA/ISRIC/ISS-CAS/JRC, 2009. Harmonized World Soil Database (version 1.1). FAO, Rome, Italy and IIASA, Laxenburg, Austria.

Fayyad, U.M., Irani, K.B., 1992. “On the handling of continuous-valued attributes in decision tree generation,” Mach. Learn. 8:87-02.

Farr, T.G., E. Caro, R. Crippen, R. Duren, S. Hensley, M. Kobrick, M. Paller, E. Rodriguez, P. Rosen, L. Roth, D. Seal, S. Shaffer, J. Shimada, J. Umland, M. Werner, 2007, The Shuttle Radar Topography Mission. Reviews of Geophysics, volume 45, RG2004, doi:10.1029/2005RG000183.

Feret J.B., Francois C., Asner G.P., Gitelson A.A., Martin R.E., Bidel L.P.R., Ustin S.L., le Maire G., Jacquemond S., 2008. PROSPECT-4 and 5: Advances in the leaf optical properties model separating photosynthetic pigments. Remote Sensing of Environment, 112, 3030-3043.

Fischer G., Shah M., van Velthuizen H., Nachtergaele F., 2001, AGRO-ECOLOGICAL ZONES ASSESSMENTS. LAND USE, LAND COVER AND SOIL SCIENCES – Vol. III - Agro-Ecological Zones Assessments

Fischer, G., H. van Velthuizen, M. Shah, F. Nachtergaele. 2002. Global Agro-ecological Assessment for Agriculture in the 21st Century: Methodology and Results. IIASA: Austria & FAO: Rome. Fisher, J.I. & Mustard, J.F 2007, ‘Cross-scalar satellite phenology from ground, Landsat, and MODIS

data’, Remote Sensing of Environment, vol. 109, pp. 261–273

M.A. Friedl, C.E. Brodley, 1997, “Decision tree classification of land cover from remotely sensed data,” Remote Sens, Environ, 61:399-409.

Gausman H.W., Allen W.A., Escobar D.C., 1974. Refractive index of plant cell walls. Applied Optics, 13, 109-111.

Hmimina G., Dufrêne, E., Pontailler, J.Y., Delpierre, N., Aubinet, M., Caquet, B., de Grandcourt, A., Burban, B., Flechard, C., Granier, A., Gross, P., Heinesch, B., Longdoz, B., Moureaux, C., Ourcival, J.M., Rambal, S., Saint André, L., Soudani, K 2013, ‘Evaluation of the potential of MODIS satellite

- 101 -

data to predict vegetation phenology in different biomes: An investigation using ground-based NDVI measurements’, Remote Sensing of Environment, vol. 132, pp. 145–158

Hosgood B., Jacquemond S., Andreoli G., Verdebout J., Pedrini A., Schmuck G., 2005. Leaf optical properties EXperimnet 93 (LOPEX93), Ispra, Italy.

Kamiński, B.; Jakubczyk, M.; Szufel, P. (2017). "A framework for sensitivity analysis of decision trees". Central European Journal of Operations Research. doi:10.1007/s10100-017-0479-6

Kidwell, K. B., (Ed.), NOAA Polar Orbiter Data User’s Guide, U.S. Dep. of Commer., NESDIS, NOAA, Natl. Clim. Data Cent., Satell. Data Serv. Div., Washington, D.C., 1998.

Knight, Edward J., and Geir Kvaran. "Landsat-8 operational land imager design, characterization and performance." Remote Sensing 6, no. 11 (2014): 10286-10305.

Kong, Xiangsheng, Yonggang Qian, and Anding Zhang. "Cloud and shadow detection and removal for Landsat-8 data." In Eighth

International Symposium on Multispectral Image Processing and Pattern Recognition, pp. 89210N- 89210N. International Society for

Optics and Photonics, 2013.

Jacquemond S., Baret F., 1990. PROSPECT:A model of leaf optical properties spectra. Remote Sensing of Environment, 34, 75-91.

Jacuemond S., Ustin S.L., Verdebout J., Schmuck G., Andreoli G., Hosgood B., 1996. Estimating leaf biochemistry using the PROSPECT leaf optical properties model. Remote Sensing of Environment, 56, 194-202.

Jaetzold, R. and Schimdt, H., 1983, “Farm Management Handbook of Kenya,” Vol. II/B. Natura Condition and Farm Management Information. Ministry of Agriculture, Kenya in Cooperation with German Agriculture Team (GAT) of the German Agency for Technical Cooperation (GTZ), Nairobi, Kenya.

Johnson, B. 2014, ‘Effects of Pansharpening on Vegetation Indices’, ISPRS Int. J. Geo-Inf. Vol. 3, pp. 507-522

Johnson, B.A., Scheyvens, H., Shivakoti, B.R., 2014. “An ensemble pansharpening approach for finer- scale mapping of sugarcane with Landsat 8 imagery,” International Journal of Applied Earth Observation and Geoinformation, 33, 218-225.

Jones H.G., 1992. Plants and microclimate (2nd ed.). Cambridge University Press, Cambridge. Pp. 428, ISBN 0521425247.

Justice, C.O., Hiernaux, P. 1983, ‘Monitoring the grassland of the Sahel using NOAA AVHRR data: Niger 1983’, Int. Journal of Remote Sensing, vol.7, pp. 1475-1498.

Justice, C.O., Holben, B.N., Gwyne, M.D. (1986). Monitoring East African vegetation using AVHRR data’. Int. Journal of Remote Sensing, vol. 7, pp. 1453-1474.

Justice, C.O., Townshead, J.R.G., Holben, B.N., Tucker, C. J 1985, ‘Analysis of the phenology of global vegetation using meteorological satellite data’, Int. Journal of Remote Sensing, vol. 6, pp. 1271- 1318.

Hsiao, T.C., Heng, L.K., Steduto, P., Rojas-Lara, B., Raes, D.and Fereres, E. 2009. AquaCrop-The FAO crop model to simulate yield response to water: III. Parameterization andtesting for maize. Agron. J. 101: 448-459.

- 102 -

Lawrence R. L., Wright A., 2001. Rule-based Classification Systems Using Classification and Regression Tree (CART) Analysis. Photogrammetric Enginerring & Remote Senssing, 67(10):1137- 1142.

Li Q., Wang C., Zhang B., Lu L., 2015, “Object-based crop classification with Landsat-MODIS enhanced time-series data,” Remoe Sensing, vol. 7, pp. 16091 – 16107.

M.S. Mkhabela, P. Bullock, S. Raj, S. Wang, Y. YangCrop yield forecasting on the Canadian Prairies using MODIS NDVI data

Agric. For. Meteorol., 151 (3) (2011), pp. 385-393

Michael Fenner, The phenology of growth and reproduction in plants, In Perspectives in Plant Ecology, Evolution and Systematics, Volume 1, Issue 1, 1998, Pages 78-91, ISSN 1433-8319, https://doi.org/10.1078/1433-8319-00053.

M. Pax-lenney, C.E. Woodcock, J.B. Collins, H. Hamdi, 1996. “The status of agricultural lands in Egypt: the use of multitemporal NDVI features derived from Landsat TM,” Remote Sens. Environ., 56, 8- 20.

Quinlan, J. R. (1987). "Simplifying decision trees". International Journal of Man-Machine Studies. 27 (3): 221. doi:10.1016/S0020-7373(87)80053-6

Rudolf, B.F.T., G.T.Batista., Wheat Yield Estimation of The Farm Level Using TM Landsat and Agrometeorological Data. Int. J.

Remote Sensing. Vol. 12, 2477-2484., 1991.

Sinclair, T.R. and Seligman, N.G. 1996. Crop modeling: from infancy to maturity. Agron. J. 88: 698- 703.

Steduto, P., Hsiao, T.C., Raes, D. and Fereres, E. 2009. AquaCrop—The FAO crop model for predicting yield response to water: I. Concepts and underlying principles. Agron. J. 101: 426–437

T. Suepa, J. Qi, S. Lawawirojwong, J.P. Messina, 2016. “Understanding spatio-temporal variation of vegetation phenology and rainfall seasonality in the monsoon Southeast Asia,” Environmental Research, 147, 621-629.

Thenkabail, P. S., Ward, A. D., Lyon, J. G., and Maerry, C. J. (1994). Thematic Mapper vegetation indices for determining soybean and corn growth parameters. Photogrammetric Engineering and Remote Sensing 60, 437–442

Twomlow, S., Mugabe, F.T., Mwale, M., Delve, R., Nanja, D., Carberry, P. and Howden, M. 2008. Building adaptive capacity to cope with increasing vulnerability due to climatic change in Africa – A new approach. Phys. Chem. Earth Part B 33: 780-787.

Vieira M. A., Formaggio A.R., Rennò C.D., Atzberger C., Aguiar D.A., Mello M.P:, 2012. Object Based Image Analysis and Data Mining applied to remotely sensed Landsat time series to map sugarcane over large areas. Remote Sensing of Environment. 2012, 123, 553-562.

Villa P., Stroppiana D., Fontanelli G., Ramin A., Brivio P. A., 2015, “In-season mapping of crop type with optical and X-band SAR data: a classification tree approach using synoptic seasonal features,” Remote Sensing, vol. 7 (10), pp. 12859-12886.

Vrieling, A., de Beurs, K.M., Brown, M.E. 2011, ‘Variability of African farming systems from phenological analysis of NDVI time series’, Climatic Change DOI10.1007/s10584-011-0049-1.

- 103 -

Wald L., 2002. Data fusion, definitions and architectures – Fusion of images of different spatial resolution. Les Presses de L’Ecole des Mines, Paris. pp. 200, ISBN 291176238X.

X. Zhang, M.A. Friedl, C.B. Schaaf, A.H. Strahler, J.C.F. Hodges, F. Gao, B.C. Reed, A. Huete, 2002. “Monitoring vegetation phenology using MODIS,” Remote Sensing of Environment, 84, 471-475.

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